Synthesis of Enantiopure 6,11‐Methylene Lipoxin B₄Methyl Ester

Abstract The synthesis of Lipoxin B 4 analogs (LXB ) to gain access stabilized inflammation resolving compounds is an actual field research. Focusing on variation and stabilization the conjugated E,Z,E,E C6–C13 tetraene moiety natural LXB , a methylene bridge introduced between C6 C11 suppresses any Z/E isomerization C8–C9 olefin. Intending enable prospective structure variations in connection with C1–C5 C14–C20 fragments, convergent total has been developed. Optically active C1–C12 building blocks were build‐up from cycloheptatriene 1‐carbonester (C6–C11, C21) glutaryl chloride (C1–C5) using Friedel‐Crafts‐type acylation chiral HPLC. C13–C20 segment had generated via five‐step sequence starting heptanoyl chloride. Horner key olefination enabled assembly carbon backbone. A final including chelate Cram reduction unsaturated ketone afforded target 6,11‐methylene methyl ester.